The present invention relates to a composition for use with wood products. More particularly, the present invention relates to a composition for use on wood products which are exposed to external weather conditions to provide at least some weather-resistant preservative effect over broad temperature and environmental exposure ranges. The present invention also pertains to a coating and preservative composition which exhibits aesthetically pleasing optic effects which vary with lighting conditions to which the applied material is exposed. Finally, the present invention relates to a wood material having such a coating integrated therewith and a process for producing the same.
Wood products for outdoor use have gained increasing popularity in recent years. Such products include, but are not limited to, structural elements such siding and window frames as well as stairs, decks, walkways, playscapes and smaller elements such as furniture and the like. For many, natural wood siding and the like provides an aesthetically pleasing alternative to brick, vinyl siding and other surface materials. Many consider wood siding and surfaces to be visually harmonious with the surrounding landscape. While wood exterior surfaces are considered desirable, in many instances such exterior surfaces have been difficult to maintain. Exterior exposed wood surfaces can be to harsh external environmental factors such as extremes in temperature, harsh wind, rain, ice and snow, degradation due to exposure to sunlight, or exposure to other environmental agents such as salt and the like.
Exposure to the external environment can cause discoloration and/or deterioration of the coating and the underlying wood material over intervals of months or years. Depending on the severity of exposure and the nature of the underlying wood material, the degradation can be of a more minimal or aesthetic nature as evidenced by undesired bleaching and/or discoloration. However) it is also possible that, in certain wood substrates and under certain conditions, the degradation can eventually affect the underlying wood structure. Severe degradation can be evidenced by erosion of the wood surface as well as splintering, splitting and/or localized rotting, mildew, etc. Such wood degradation can curtail or limit the useful life of the wood product necessitating frequent repair and/or replacement of the wood itself.
In order to eliminate or minimize this, various wood coating and sealing materials have been proposed and employed. Typically, the materials are employed to enhance the color or beauty of the wood product and/or to minimize adverse interaction between the wood product and water. These products typically are formulated to coat the outer surface of the wood product to which they are applied and to impart either a gloss or satin finish to the wood material so treated. One drawback of such products is the inability of the applied coating to withstand extremes in temperature. Thus while a material may provide initial protection, it is unable to withstand the expansion and contraction caused by repeated temperature cycles. Additionally, typical coating materials do not exhibit suitable xe2x80x9cwearabilityxe2x80x9d over extended periods. Such coating products do not exhibit significant resistance to wear and erosion caused by exposure to wind, rain, abrasion and the like.
It has also been desirable to employ logs and roughhewn wood as exterior siding material on various buildings. Such material can have an extremely rough and irregular surface which can make it susceptible to weathering and degradation while also making it extremely difficult to protect effectively. Various lacquers and coating products have been proposed for use on such materials. They have been fraught with various drawbacks such as short lifespan and/or producing high glare surfaces when viewed in direct sunlight. Such high glare surfaces detract from the appeal of the natural roughhewn surface of the material.
Thus it would be desirable to provide a coating composition which is aesthetically pleasing and can be used with various types of wood in a variety of end use applications. It would also be desirable to provide a composition which is durable over a wide range of temperatures and over multiple temperature change cycles. It would also be desirable to provide a composition which would enhance and preserve the underlying wood substrate and would minimize or prevent at least some deleterious interaction between the wood substrate and the surrounding environment. Finally, it would be desirable to provide a wood material with a weather and wear resistant outer surface which has a durable coating composition intimately integrated into the wood surface and in continuous overlying relationship thereto as well as a method for producing such wood material.
A composition for application on a wood surface is proposed which comprises a major portion of an unsaturated glyceride derivative of at least one of stearic acid and eleostearic acid in mixture with a minor portion of an unsaturated glyceride derivative of at least one of linoleic acid, linolenic acid, and oleic acid; a minor portion of wood penetrating material comprising at least one C16 to C20 fatty acid derivative. The major and minor portions are preferably present in admixture with an aliphatic hydrocarbon solvent having a boiling point between 200xc2x0 F. and 350xc2x0 F.
The major portion of an unsaturated glyceride derivative of at least one of stearic acid and eleostearic acid glyceride derivative is present in an amount sufficient to provide at least some abrasion resistance and water impermeability. The minor portion of the unsaturated glyceride derivative of a fatty acid selected from the group which includes linoleic acid, linolenic acid, and oleic acid is present in an amount sufficient to maintain the materials in suitable admixed relationship during application of the composition. The liquid hydrocarbon is present in an amount sufficient to enhance penetration of the composition components into grain structure and interstices present in the wood substrate. The aliphatic hydrocarbon solvent component is present in an amount sufficient to maintain the major portion and minor portions in dispersed relationship with one another.
A method for preparing and preserving a wood surface is also proposed in which an amount of a composition containing an unsaturated glyceride derivative of at least one of stearic acid and eleostearic acid, an unsaturated glyceride derivative of a fatty acid from the group which includes linoleic acid, linolenic acid, and oleic acid; a wood penetrating material comprising at least one C16 to C20 fatty acid derivative; and an aliphatic hydrocarbon solvent component having a boiling point between 200xc2x0 F. and 350xc2x0 F. is brought into contact with an exposed wood surface in a plurality of discrete discrete application steps. The amount of the composition applied in at least one first application step is that sufficient to saturate the wood region adjacent to the wood surface. After application, the wood surface is permitted to dry. At least one additional application of the composition is applied over the wood surface after thorough drying. The quantity of material applied in the at least one additional amount is sufficient to draw into the wood region adjacent to the surface of the wood and to impart a light finish over at least a portion of the exterior wood surface. At least one final coat may be applied in over lying relationship to the additional applied coat. The at least one final coat is applied in an amount sufficient to impart a luster quality to the applied coating material.
Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.